To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Coin Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins is 98.85 euros.
- In the past, hammer prices have varied significantly, ranging from 42 euros to 600 euros, although the latter seems to be an outlier.
- Most hammer prices for coins with similar condition (80) have been in the range of 40 to 130 euros.

3. Starting Price: The current starting price is 35 euros, which is relatively low compared to the average hammer price.

4. Sales Trends: The coin has been auctioned 24 times, of which 18 have sold. This indicates good demand and sustained interest in the coin.

5. Previous Prices: In previous auctions, coins with a condition of 80 have reached hammer prices of up to 130 euros.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 100 to 130 euros, considering that the condition is good and that interest in the coin appears to be solid. Therefore, a reasonable maximum purchase price could be 120 euros.